As wireless technology develops increasingly and laptop computer popularizes progressively, it becomes more and more popular to access the Internet by using a laptop computer. The WIMAX is a new Third Generation (3G) mobile communication standard, and as there are some problems with network coverage of current WIMAX, in order to meet user's requirement of accessing the Internet anytime and anywhere, it is quite necessary to use the dual-mode terminal adopting the WIMAX and another mode, for example, the dual-mode terminal with the WIMAX and an Evolution Data Only (EVDO) modes. The full name of the EVDO is CDMA2000 1xEV-DO, which is a stage of CDMA2000 1x evolution.
In the dual-mode terminal with the WIMAX and another mode, a diversity function is added in order to improve signal quality, that is, the antenna includes a main antenna and an auxiliary antenna of the WIMAX, and a main antenna and an auxiliary antenna of another mode. The main antenna of the WIMAX and that of another mode are generally called main antennas, and the auxiliary antenna of the WIMAX and that of another mode are generally called auxiliary antennas. The main antennas are responsible for signal emission and signal reception, and the auxiliary antennas serve as reception diversity. In the present situation that space of the antenna reserved in a terminal product becomes smaller and smaller, how to dispose the antenna reasonably, to make the antenna meet layout requirement of the Printed Circuit Board (PCB), structure requirement and antenna performance index requirement, has became an urgent issue.
FIG. 1 shows an antenna structure of an existing dual-mode terminal. The antenna structure has two antenna brackets, wherein the antenna bracket 1 is used for fixing the main antennas including the main antenna of the WIMAX and that of another mode; and the antenna bracket 2 is used for fixing the auxiliary antennas including the auxiliary antenna of the WIMAX and that of another mode. The main antenna of the WIMAX operates at an emission frequency band and a reception frequency band of the WIMAX, and the main antenna of another mode operates at the emission frequency band and the reception frequency band corresponding to the another mode, for example, the main antenna of the EVDO operates at the emission frequency band and reception frequency band of the EVDO. The auxiliary antenna of the WIMAX operates at a reception diversity frequency band of the WIMAX, and the auxiliary antenna of the another mode operates at the reception diversity frequency band corresponding to the another mode for example, the auxiliary antenna of the EVDO operates at the reception diversity frequency band of the EVDO.
With the development of the terminal product, requirement for an area of the PCB occupied by the antenna becomes more and more strict, that is, it is required that the area of the PCB occupied by the antenna should be as small as possible, but an existing antenna structure cannot meet such requirement well. Besides, an existing antenna in a reception mode has serious signal interference and loss problems.